Vehicle drivetrain differential assembly

Abstract

A differential assembly includes a first case rotatable about an axis and defining a first mounting flange having a through hole and a second case abutting the first case to define a gear nest cavity therebetween. The second case further defines a second mounting flange having a through hole and formed to mate to the first mounting flange. The differential assembly also includes a ring gear mounted to the first mounting flange and fastener extending through the through hole of both the first mounting flange and second mounting flange into a fastener hole of the ring gear. Additionally, the first mounting flange is sandwiched between the second mounting flange and the ring gear.

What is claimed is: 
     
       1. A differential assembly comprising:
 a first case rotatable about an axis and defining a first mounting flange having a through hole; 
 a second case abutting the first case to define a gear nest cavity therebetween, the second case further defining a second mounting flange having a through hole and formed to mate to the first mounting flange; 
 a ring gear mounted to the first mounting flange; and 
 a fastener extending through the through hole of both the first mounting flange and second mounting flange into a fastener hole of the ring gear, wherein the first mounting flange is sandwiched between the second mounting flange and the ring gear, the first case and the second case cooperate to define a spider shaft hole that receives a shaft of a spider that rotatably supports a pinion gear, and a gap is located between the first case and the second case that extends away from the axis from the spider shaft hole and from an end of the shaft of the spider that faces away from the axis. 
 
     
     
       2. The differential assembly of  claim 1  wherein the fastener includes a threaded portion near a distal end that engages the fastener hole. 
     
     
       3. The differential assembly of  claim 2  wherein each through hole of the first mounting flange and the second mounting flange are unthreaded and provide clearance to a shank portion of the fastener. 
     
     
       4. The differential assembly of  claim 1  wherein the first case defines a first nesting feature and the second case defines a second nesting feature, and the first nesting feature is configured to engage the second nesting feature during assembly to self-align the first case with respect to the second case. 
     
     
       5. The differential assembly of  claim 4  wherein the first nesting feature and the second nesting feature are each oriented to be substantially parallel to the axis. 
     
     
       6. The differential assembly of  claim 4  wherein the first nesting feature and second nesting feature engage to radially align the first case to the second case. 
     
     
       7. The differential assembly of  claim 4  wherein the first nesting feature defines an inside diameter relative to the axis that is substantially equal to an outside diameter of the second nesting feature. 
     
     
       8. The differential assembly of  claim 4  wherein the ring gear defines a third nesting feature that engages an axially-extending portion of the first nesting feature during assembly to self-align the ring gear with respect to the first case. 
     
     
       9. The differential assembly of  claim 1  wherein the ring gear further comprises a set of teeth that overhangs the fastener hole in a manner that prevents the fastener from being inserted into the fastener hole before being inserted through one of the through holes. 
     
     
       10. The differential assembly of  claim 1  wherein the first case defines an axially-extending first nesting feature that is sandwiched between the second case and the ring gear in a radial direction relative to the axis. 
     
     
       11. The differential assembly of  claim 1  wherein the fastener has a head and a shank that extends from the head, wherein the head is disposed adjacent to the second mounting flange and the shank extends through the through holes of the first and second mounting flanges and the fastener hole. 
     
     
       12. The differential assembly of  claim 1  wherein the first case and the second case are arranged to maintain an axial gap therebetween at all areas closer to the axis than the first mounting flange and the second mounting flange. 
     
     
       13. A differential assembly comprising:
 a first case rotatable about an axis and defining a first nesting portion; 
 a second case defining a second nesting portion that contacts and nests with the first nesting portion; 
 a ring gear mounted to the first case and configured to nest with the first nesting portion; and 
 a fastener extending through the first case and the second case into a fastener hole of the ring gear, wherein the first case is sandwiched between the second case and the ring gear, the first case and the second case cooperate to define a spider shaft hole that receives a shaft of a spider that rotatably supports a pinion gear, and a gap is located between the first case and the second case that extends away from the axis from the spider shaft hole and from an end of the shaft of the spider that faces away from the axis to the second nesting portion such that the gap is completely disposed further from the axis than the spider shaft hole is disposed from the axis. 
 
     
     
       14. The differential assembly of  claim 13  wherein each of the first nesting portion and the second nesting portion includes a radially-extending mounting flange defining a through hole and the fastener extends axially through the through hole of the second nesting portion and the first nesting portion into the ring gear. 
     
     
       15. The differential assembly of  claim 14  wherein the radially-extending mounting flange of the first nesting portion is sandwiched between the radially-extending mounting flange of the second nesting portion and the ring gear. 
     
     
       16. The differential assembly of  claim 13  wherein the first nesting portion defines an axially-extending first nesting feature configured to engage the second nesting portion during assembly to self-align the first case with respect to the second case. 
     
     
       17. The differential assembly of  claim 16  wherein the first nesting feature defines an inside diameter substantially equal to an outside diameter of the second nesting portion. 
     
     
       18. The differential assembly of  claim 16  wherein the ring gear engages the axially-extending first nesting feature to radially align the ring gear to the first case. 
     
     
       19. The differential assembly of  claim 16  wherein the axially-extending first nesting feature is sandwiched between the second case and the ring gear in a radial direction relative to the axis. 
     
     
       20. The differential assembly of  claim 13  wherein the ring gear defines an inner diameter substantially equal to an outer diameter of the first nesting portion.